ATX TAXIES OVER SNOW RIDGE; DAMAGED TAIL CONE.

Narrative

I WAS THE PLT OF A PART 135 FLT ORIGINATING AND TERMINATING IN OMAHA; NE (OMA) WITH STOPS IN LINCOLN; NE (LNK) AND KANSAS CITY; MO (MKC). ARRIVING AT THE LINCOLN ARPT; I LANDED RWY 35L. I EXITED THE RWY AT TXWY K AND TAXIED TO THE RAMP. THE VISIBILITY ON THE GND WAS APPROX 1 1/2 MI; WITH PERIODS OF LOWER VISIBILITY DUE TO INCREASED SNOWFALL; BLOWING SNOW AND/OR BOTH. THE RAMP HAD NOT BEEN PLOWED AND CONTAINED SNOW DRIFTS; I ESTIMATED AT OVER 12 INCHES. I WAITED FOR THE COURIER. DURING THIS TIME I NOTED THAT THE SNOW PLOWS HAD BEGUN WORK ON THE RAMP. AFTER LOADING THE FREIGHT I TAXIED TO WHAT I BELIEVED AT THE TIME TO BE THE RAMP TXWY. THERE WAS A SNOW RIDGE OF APPROX 24 INCHES ON THE EDGE OF THE TXWY; AND SEEING NO ALTERNATIVE; I TAXIED OVER IT. THE NOSE WENT UP HIGHER THAN I EXPECTED; BUT NOT ENOUGH TO ALARM ME. ARRIVING IN KANSAS CITY I WALKED AROUND THE AIRPLANE AND SPENT EXTRA TIME INSPECTING THE AIRPLANE'S PROPS; WINGTIPS; AND THE LNDG GEAR; NOTING NO DAMAGE. I RETURNED TO OMA. WHEN I GOT BACK TO OMAHA; THE AIRPLANE WAS PUT IN A HANGAR WHERE I CONDUCTED THE POST-FLT INSPECTION. IT WAS NOT UNTIL THIS TIME THAT I COULD SEE THAT THE TAIL CONE OF THE AIRPLANE HAD BEEN CRACKED ALONG THE BOTTOM SIDE; AND THE METAL THAT THE TAIL TIE-DOWN WAS ATTACHED TO WAS SLIGHTLY BENT. THERE WAS A SMALL AMOUNT OF DIRT AND GRASS IN THE PLASTIC PORTION OF THE TAIL STRIKE. I NOW REALIZED THAT I HAD PROBABLY NOT TAXIED TO THE RAMP TXWY. IN REVIEWING THE TAXI DIAGRAM; I CONJECTURE THAT I HAD INSTEAD TAXIED ACROSS THE RAMP TXWY AND THEN ACROSS A HELIPAD THAT IS LOCATED BTWN THE 2 TXWYS; ACTUALLY CUTTING ACROSS A SMALL GRASS AREA BTWN THE PARALLEL TXWY AND THE HELIPAD. I HAD NO IDEA THAT ANYTHING ON THE ACFT HAD SUSTAINED DAMAGE. IF I HAD THOUGHT THAT WAS A POSSIBILITY; I WOULD HAVE TAXIED BACK TO THE RAMP IN LNK. MY INSPECTION OF THE ACFT IN MKC WAS SOMEWHAT CURSORY; AND IT NEVER OCCURRED TO ME TO LOOK AT THE BOTTOM SIDE OF THE TAIL BECAUSE THE HT IT SITS OFF THE RAMP; I WOULD NEVER HAVE BELIEVED THAT IT WAS POSSIBLE TO HAVE NOSED UP HIGH ENOUGH TO CAUSE IT DAMAGE. I HAVE OFTEN WONDERED WHAT THE RATIONALE IS OF KEEPING A RWY CLR FOR LNDG; BUT NOT CLRING AN AREA FOR AN AIRPLANE TO TAXI TO AFTER EXITING THE RWY. IF I HAD THIS TO DO OVER AGAIN; I WOULD HAVE REFUSED TO TAXI ON THE RAMP UNTIL A PLOW COULD BE DISPATCHED TO CLR ME A WAY TO TAXI ONTO; AND OFF OF THE RAMP.